Endnotes + 

At a bullfight the seats in the sun are the cheaper, those in the shade being double the price. ↩ + 

In the story, as it appeared in serial form, the name of the poison occurred. It has been represented to the author (and he agrees) that it is wholly undesirable that the name of this drug should appear in a work of fiction. It is one well known to oculists and its action is faithfully described in these pages. ↩ + 

Busy: a busy fellow, detective. ↩ + 